Dental restoration



Oqt. 9, 1934. F. G. NEUROHR DENTAL RESTORATION Filed Dec. 6, 1950 INVENTOR FERDINAND 6'.

IVEUR ORNEY Patented Oct. 9, 1934 UNHTED STATES PATENT OFFICE DENTAL RESTORATION Ferdinand G. Neurohr, Hollis, N. Y. Application December 6, 1930, Serial No. 500,463 4 Claims. (01. 32-12) This invention relates to improvements in den- Fig. 2 is a plan view thereof. tal restorations and has particular reference to Fig. 3 is a longitudinal section, the dotted line a removable bridge-work construction. position of the bridge-work showing the manner Two general types of removable appliances are of inserting and removing the same.

in common use at the present time, one of which Fig. 4 is afront elevation of the bridge-work. utilizes clasps for securing the bridge-work in po- Fig. 5 is a side view of the posterior inlay and sition, while the other depends upon frictional abutment tooth, contact between the male and female rests of the Fig. 6 is an elevation of the posterior end of bridge-work and the inlays on the abutment teeth. the bridge-work. I

10 h a ma y advanta s whi h. n the wh l Fig. 7 is a side view of the anterior inlay and have made them quite effective in their appliab tment tooth. cation to restoration cases that have indicated Fig. 8 is a fragmentary longitudinal section of their adeptabilitye a p the 0 p typ a slightly different form of the anterior portion is easily removed and inserted; and it does not of th restoration, and

15- neoessitate a great m n of pr tr atm n f Fig. 9 is a side elevation of the anterior inlay the abutment teeth as no high degree of precision and b t e t tooth ho in Fig 3 in the paralleling of the attachments is required, In carrying out the invention, the anterior and with the result that it offers the requ te pu p posterior abutment teeth 10 and 11, respectively, protection to the abutment teeth and eliminates are prepared in the usual manner for the recep- 29 friction as a retentive factor in the designing of tion of inlays l2 and 13, it being noted that in th appliance H w v t a plish t s s t the preparation of said teeth, the interproximal isfaetely results, Clasps are required, a d it is boxes 14 thereof need be only of a very slight a W ll r iz f hat, l hou h th ir us at depth due to the elimination of friction as a rem s ak s possible to incorporate Vital fear tentive factor in holding the bridge-work in posi- 25- tures in the construction of a restoration, they do tion, In this manner, there is insured a, maxinot otherwise add to the desirability of the apmum ul protection of the abutment teet pliance. The bridge-Work generally indicated by the The undesirable features of clasps have been um l 15 comprises the usual saddle 16, and eliminated n the r c n ype of appliances but strut 17 upon which the teeth thereof are mount- 30 the l t on th t r ha d, d n t p ss ss t ed in the customary manner. At the ends of the same case of removal and insertion and d o strut are provided the male rests 18 and 19 which ive as much fr edom to the abutment t e h. are adapted to loosely fit, as distinguished from Furthermore, with the f c pp there frictional engagement, into the anterior and posexists the absolute necessity of precision parallelt ri r inlays 12 and 13 which have the female g of the a s o the rests and more extensive rests 20 and 21, respectively, to receive said male abutment preparations due to the demand for t reater retention and Spa a e sa y y In the formation of the female rest 20, the the friction factor and other features in the deb e 22 thereof may be made horizontal or, prefsign of these appliances. erably, this surface is slightly inclined downwardto It is n object of the p n nv n i n to p ly in a pulpal direction relative to the tooth in vide an improved restoration which will incorpoas shown in Figs, 3 and 8, The base of the male rate the desirable features of the above menre t 13, which engages the surface 22, is corretiohed yp at the some time, avoid the spondingly inclined so that when the bridge-work Objections O by eliminating h u e Of a p is in position, the pressure exerted thereupon by nd h d f a s u pa l l n n so d the action of mastication will not have a tendency the present appliance See lres a m p p to dislodge the bridge-work from its support on a periodontal protection; is y to remove and said base 22. Further, the facial and lingual walls insert; and offers complete resistance to displace- 23 a d 24 (Fig, 7) of the female rest 20 and the m rit du n the process of mastication. corresponding walls of the rest 18, converge to- The invent ve ea i ap b e Of receiving a ward the bases of the rests, and the pulpal wall 25 variety of mechanical expressions, some of which of id rest 20, together with the adjacent wall are shown in the a mp ny n aw n Where! 26 of the rest 18, areinclined from the bases of Fig. 1 is a front elevation of a restoration conth respective rests in a pulpal direction. Thus, structed n ac o da c W h invention and the male and female rests are of substantially the showing the same in position. same configuration and, by reason of the fact that 1.10

inlays diverge relative to each no dependence is placed upon friction to hold the male rest in place and precision paralleling of the walls of said rests is consequently unnecessary, said walls may be inclined as described to permit of the easy insertion of the rest 18 into the rest 20. In order to provide interlocking engagement between the anterior rest 18 and its associated inlay, the former is provided on the wall 26 adjacent the occlusal surface thereof, with a locking extension 27 which fits into alrecessor depression 28 in the pulpal wall 25 of the female rest.

place, as indicated in dotted lines in Fig. 3, and thereafter prevents accidental displacement of the anterior end of the bridge-work.

Figs. 8 and 9 illustrate a slightly different con struction of anterior loci; but, as in the form shown in Fig. 3, the base 29 of the femalarest and that of the male rest 30 are inclined downwardly in a pulpal direction. The abutting pulpal walls 31 of the rests are of concavo-convex formation, in a vertical direction sothat the wall of the female rest will act as a guide for the pivotal movement of the bridge-work when being inserted into position and said walls will combine to lock the anterior end of said bridge-work against accidental displacement.

At the posterior end of the restoration, the facial, lingual and pulpal walls 32, 33 and 34, respectively, of the female rest 21 are all inclined in substantially the same manner as described in connection with the anterior rest 20, and the .male rest 19, which engages in the female rest, has its walls correspondingly inclined. lhus, the pulpal walls of the rests in the anterior and posterior other from the bases of the rests and thereby afford sufficient clearance for the bridge-work as it is swung into position. I

In addition to the formation of the walls of the rests at the distal end of the restoration, just described, there is provided an interlocking engagement between said rests which is designed to prevent any distal pressure upon the abutment tooth 11 from causing a drifting movement of said tooth which would result in the displacement of the female rest of the inlay 13. To this end, the bases of the rests l9 and 21 are provided, respectively, with the flanges 35 and 36 which interengage as shown in Fig. 3 when the bridge-work is in position. In this manner, any tendency of the tooth ll to drift, away from the bridgewlork is prevented by the engagement of the flange 36 with the flange 35.

As a means for locking the bridge-work in its position between the abutment teeth, which means at the same time will be easy to manipulate in order to release said bridge-work, there is preferably employed a spring detent 3'7 'madeof. any suitable material.

One end of this detent is secured, as by soldering, to the strut 17 on the facial side thereof and extends occlusally and in such relation to the adjacent tooth of the bridge work that when the latter is in position saiddetent will be interproximately located with respect to said tooth and the inlay 13 of the abutment tooth. The free end of the detent is so disposed that as the bridge-work is being inserted and approaches its proper position, said end will engage and ride over the adjacent portion of the inlay 13 and be thus placed under a slight tension. Then, as the bridge-work, becomes properly This interlocking engagement is effected when the bridge-work 15 is being mounted in seated, said end of the detent will snap into engagement with a shoulder 38 formed on the interproximal surface of said inlay, as best illustrated in Fig. 1. In this position, the detent locks the bridge-work in place and reduces to a minimum any possibility of it becoming accidently detached during the process of mastication. In order to facilitate removal of the bridge-work, the detent, adjacent its free end, is provided with a'small lateral extension 39 which may be engaged by a finger or thumb to exert a slight pres sure upon the detent in a mesial direction so as to disengage the detent from said shoulder, whereupon the bridge-work may be withdrawn.

' without departing from the spirit or scope of ,the invention, it will be understood that, although the bridge-work has been shown and described in the position wherein the detent 3'? thereof is associated with the posterior abutment tooth, the restoration including the abutment teeth, inlays therefor and the bridge-work may be prepared so as to accomplish a reversal of the position of the bridge-work, or, in other words, so that the detent will engage with the inlay of the anterior abutment tooth rather than the posterior inlay.

What is claimed is:

1. In a dental restoration, anterior and posterior inlays having female rests in which the pulpal walls diverge relative to each other from the bases ofv said rests, the pulpal wall of one of said rests having a depression therein, a bridgework having male rests insertable into said female rests, one of said male rests being provided with a projection engageable in said depression, and aspring detent carried by said bridge-work and engaging the inlay adjacent the other of said male rests in an interproximal position relative to the latter inlay and the next adjacent tooth of said bridge-work.

2. In a dental restoration, anterior and posterior inlays having female rests, a bridge-work insertable between said inlays and having male rests extending into the first named rests, said bridge-work andthe pulpal wall of the rest of said anterior inlay having co-operating means constituting an anterior lock for the bridge-work, and a spring detent extending occlusally from said bridge-work and engageable with said posterior inlay.

3. In a dental restoration, anterior and posterior inlays having female rests, a bridge-work engageable between said inlays and having male restsextending into said female rests, the posteriorv male rest and the base of the adjacent female rest having interlocking extensions, and the pulpal wall of the anterior female rest and associated male rest having co-operating means constituting an anterior lock for the bridge-work, and a spring detent extending occlusally from said. bridge-work and engageable, with said posterior inlay.

4. In a dental restoration, inlays having female rests, a bridge-work insertable between said inlays and having male rests extending into the first-named .rests, said bridgework and the pulpal wall of the rest of one of said inlays having FERDINAND Gr. NEUROHR. 

